KITLG and neoplasm: In the tumor-driven microenvironment, proinflammatory cytokines such as prostaglandin-E2 (PG-E2), macrophage colony-stimulating factor (M-CSF), granulocyte colony-stimulating factor (G-CSF), GM-CSF, stem cell factor (SCF), and vascular endothelial growth factor (VEGF) are involved in the induction of chronic inflammation in cancer26.